/// <summary>
/// Transfers settings contained in this into a <see cref="CallOptions"/>.
/// </summary>
/// <param name="baseSettings">The base settings for the call. May be null.</param>
/// <param name="callSettings">The settings for the specific call. May be null.</param>
/// <param name="clock">The clock to use for deadline calculation.</param>
/// <returns>A <see cref="CallOptions"/> configured from this <see cref="CallSettings"/>.</returns>
internal static CallOptions ToCallOptions(this CallSettings baseSettings, CallSettings callSettings, IClock clock)
{
CallSettings effectiveSettings = baseSettings.MergedWith(callSettings);
if (effectiveSettings == null)
{
return default(CallOptions);
}
var metadata = new Metadata();
effectiveSettings.HeaderMutation?.Invoke(metadata);
return new CallOptions(
headers: metadata,
deadline: effectiveSettings.Timing.CalculateDeadline(clock),
cancellationToken: effectiveSettings.CancellationToken ?? default(CancellationToken),
writeOptions: effectiveSettings.WriteOptions,
propagationToken: effectiveSettings.PropagationToken,
credentials: effectiveSettings.Credentials);
}
/// <summary>
/// This method merges the settings in <paramref name="overlaid"/> with those in
/// <paramref name="original"/>, with <paramref name="overlaid"/> taking priority.
/// If both arguments are null, the result is null. If one argument is null,
/// the other argument is returned. Otherwise, a new object is created with a property-wise
/// overlay, where null values do not override non-null values.
/// Any header mutations are combined, however: the mutation from the original is
/// performed, then the mutation in the overlay.
/// </summary>
/// <param name="original">Original settings. May be null.</param>
/// <param name="overlaid">Settings to overlay. May be null.</param>
/// <returns>A merged set of call settings, or null if both parameters are null.</returns>
public static CallSettings MergedWith(this CallSettings original, CallSettings overlaid)
=> CallSettings.Merge(original, overlaid);
/// <summary>
/// Merges the settings in <paramref name="overlaid"/> with those in
/// <paramref name="original"/>, with <paramref name="overlaid"/> taking priority.
/// If both arguments are null, the result is null. If one argument is null,
/// the other argument is returned. Otherwise, a new object is created with a property-wise
/// overlay. Any header mutations are combined, however: the mutation from the original is
/// performed, then the mutation in the overlay.
/// </summary>
/// <param name="original">Original settings. May be null.</param>
/// <param name="overlaid">Settings to overlay. May be null.</param>
/// <returns>A merged set of call settings.</returns>
internal static CallSettings Merge(CallSettings original, CallSettings overlaid)
{
if (original == null)
{
return overlaid;
}
if (overlaid == null)
{
return original;
}
return new CallSettings(
overlaid.CancellationToken ?? original.CancellationToken,
overlaid.Credentials ?? original.Credentials,
overlaid.Timing ?? original.Timing,
// Combine mutations so that the overlaid mutation happens last; it can overwrite
// anything that the previous mutation does.
original.HeaderMutation + overlaid.HeaderMutation,
overlaid.WriteOptions ?? original.WriteOptions,
overlaid.PropagationToken ?? original.PropagationToken);
}